Clinical and radiological outcomes of antegrade posterior column screw fixation of the acetabulum.

INTRODUCTION

Antegrade posterior column screw fixation (APCS) provides stable fixation while reducing the complications related to dual acetabular approaches. The objective of this study was to present the radiological and clinical outcomes of fixation of the posterior column of the acetabulum through a single anterior approach.

HYPOTHESIS

APCS will produce better clinical and radiological outcomes relative to not placing any screws in the posterior column.

PATIENTS AND METHODS

This was a retrospective single-center study of 69 patients operated through a single anterior approach for a both-column fracture of the acetabulum between 2014 and 2018. Patients were divided into two groups (APCS+, n=24 and APCS-, n=45) depending on whether the posterior column was fixed with an antegrade lag screw or not. The radiological outcomes were defined by the quality of the reduction according to Matta. The clinical outcomes were evaluated using the Harris Hip score and Merle Postel D'Aubigné (MDP) score at the final assessment. A sequential hierarchical analysis was done with a Chi test for the radiological criterion and Student's t test for the clinical outcomes.

RESULTS

In the APCS+ group, the reduction was anatomical in 71% (17/24) of patients, imperfect in 12% (3/24) and poor in 17% (4/24). In the APCS- group, the reduction was anatomical in 33% (15/45) of patients, imperfect in 31% (14/45) and poor in 35% (16/45). This difference between groups was statistically significant (p=.012). The differences between groups in the Harris (p=.201) and MDP (p>.05) scores were not significant. Mean irradiation in the APCS+ group was significantly higher (114.8 cGy.cm) relative to the APCS- group (39.8 cGy.cm) (p<.001). None of the patients in the APCS+ group underwent a subsequent total hip arthroplasty, while 8 patients from the APCS- group did (p=.031). The differences in the postoperative complications were not statistically significant.

DISCUSSION

APCS yields satisfactory radiological and clinical outcomes without increasing the complication rate; this must be balanced out against the additional irradiation.

LEVEL OF EVIDENCE

III.